System and method for protecting against impact between a vehicle and a facility for housing the vehicle

ABSTRACT

A method of protecting against impact between a vehicle and a physical structure of a facility having an opening for the vehicle to pass through includes defining a monitored plane relative to an edge of the opening, the monitored plane defined by a plurality of baseline measurements, wherein each of the plurality of baseline measurements: 1) corresponds to a distance between a sensor spaced apart from the edge and one of a plurality of virtual ends of the monitored plane, and 2) is identified by an angle parameter. The method also includes obtaining a subsequent measurement; evaluating the subsequent measurement relative to a corresponding baseline measurement to determine if a criterion indicative of an intrusion of the monitored plane is satisfied; and activating an alarm when the criterion is satisfied.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation-in-part of U.S. patent applicationSer. No. 16/550,125, filed Aug. 23, 2019, for “System and Method forProtecting Against Impact Between a Moving Vehicle and a Facility forHousing the Vehicle,” the entire disclosure of which is incorporatedherein by reference.

TECHNICAL FIELD

The present disclosure relates generally to protecting against impactbetween a moving vehicle and a facility for housing the vehicle, andmore particularly, to systems and methods that protect the structuralintegrity of both aircraft and aircraft facilities, such as hangars, asaircraft are moved around within such facilities.

BACKGROUND

Aviation ground handlers move aircraft of all shapes and sizes hundredsof thousands of times each day; across ramps, in and out of hangars, andto and from maintenance facilities. While usually done safely, aircraftunder tow occasionally impact buildings, hangars, other aircraft, orequipment. “Hangar rash,” as it is commonly referred to, is thought tobe the largest source of damage to the worlds fleet of aircraft.Insurance company claims easily extend into the hundreds of thousands ofdollars in damages per incident. Many more incidents go unclaimed.

With reference to FIG. 1A, an aircraft located within a hangar may betowed about the hangar by an aircraft tug under control of an aircrafttug operator. The aircraft tug and operator are situated at the nose ofthe airplane. As such, the view of the operator in the direction of thetail of the airplane is partially obstructed is areas between the noseand the wings, and fully obstructed in areas beyond the wings. Inaddition, depth perception is difficult at the distances associated withthe size of larger aircraft, all of which makes it difficult to see thewings and tail.

With reference to FIG. 1B, because of the obstructed views the aircrafttug operator may inadvertently over tow the airplane toward the backwall of the hangar thereby causing the tail to impact the back wall.Such impact may result in damage to one or both of the aircraft and thehangar wall.

It is therefore desirable to assist aircraft tug operators to preventincidents of over towing and protect against impact between aircraft andthe facilities that house aircraft. The concepts disclosed below addressthese needs and others.

SUMMARY

The system and method described herein are designed to provide advancednotice to ground crew members, moving aircraft under tow within afacility, when a collision with a structure of the facility or an objectwithin the facility is imminent. The system and method act as an earlydetection and warning system to notify ground crew members when a partof the aircraft under tow is within a pre-determined distance of astructure or object. The system and method provides both visual andaural warnings to alert ground crew members of an impending collision.

In one aspect of the disclosure, a method of protecting against impactbetween a vehicle and a physical structure, e.g., a wall, of a facilityhaving an opening or doorway for the vehicle to pass through, includesdefining a monitored plane relative to one or more edges of the opening.The monitored plane is defined by a plurality of baseline measurements,wherein each of the plurality of baseline measurements: 1) correspondsto a distance between a sensor spaced apart from the edge and one of aplurality of virtual ends of the monitored plane, and 2) is identifiedby an angle parameter. The method also includes obtaining a subsequentmeasurement; evaluating the subsequent measurement relative to acorresponding baseline measurement to determine if a criterionindicative of an intrusion of the monitored plane is satisfied; andactivating an alarm when the criterion is satisfied.

In another aspect of the disclosure, a system for protecting againstimpact between a vehicle and a physical structure of a facility havingan opening or doorway for the vehicle to pass through includes ameasurement module and a detection module. The opening is defined by aplurality of edges of the physical structure and measurement module isconfigured to be spaced apart from one of the plurality of edges. Themeasurement module is further configured to rotate relative to the edge,and obtain a plurality of measurements, wherein each of the plurality ofmeasurements corresponds to a distance from the measurement module.

The detection module is coupled to the measurement module and comprisesa definition module that defines a monitored plane relative to the edge.The monitored plane is defined by a plurality of baseline measurements,wherein each of the plurality of baseline measurements: 1) correspondsto a distance between the measurement module and one of a plurality ofvirtual ends of the monitored plane, and 2) is identified by an angleparameter. The detection module is configured to obtain a subsequentmeasurement from the measurement module; associate an angle parameterwith the subsequent measurement; evaluate the subsequent measurementrelative to a corresponding baseline measurement having a same angleparameter to determine if a criterion indicative of an intrusion of themonitored plane is satisfied; and output an alarm activation signal whenthe criterion is satisfied.

In another aspect of the disclosure, a method of protecting againstimpact between a vehicle and a physical structure, e.g., wall, of afacility having an opening or doorway for the vehicle to pass throughincludes defining a monitored frame relative to at least one of theinside surface and the outside surface the physical structure. Themonitored frame is defined by a plurality of sets of baselinemeasurements, wherein each of the plurality of sets of baselinemeasurements is identified by an angle parameter and includes at leastone baseline measurement that corresponds to a distance between a sensorspaced apart from the surface and one of a plurality of virtual ends ofthe monitored frame. The method also includes obtaining a subsequentmeasurement; evaluating the subsequent measurement relative to acorresponding set of baseline measurements to determine if a criterionindicative of an intrusion of the monitored frame is satisfied; andactivating an alarm when the criterion is satisfied.

In another aspect of the disclosure, a system for protecting againstimpact between a vehicle and a physical structure of a facility havingan opening for the vehicle to pass through includes a measurement moduleand a detection module. The measurement module is configured to bespaced apart from at least one of an inside surface and an outsidesurface of the physical structure. The measurement module is furtherconfigured to rotate relative to the surface; and obtain a plurality ofmeasurements, wherein each of the plurality of measurements correspondsto a distance from the measurement module.

The detection module is coupled to the measurement module and comprisesa definition module that defines a monitored frame relative to thesurface. The monitored frame is defined by a plurality of sets ofbaseline measurements, wherein each of the plurality of sets of baselinemeasurements is identified by an angle parameter and includes at leastone baseline measurement that corresponds to a distance between a sensorspaced apart from the surface and one of a plurality of virtual ends ofthe monitored frame. The detection module is configured to obtain asubsequent measurement from the measurement module; associate an angleparameter with the subsequent measurement; evaluate the subsequentmeasurement relative to the set of baseline measurements identified bythe angle parameter associated with the subsequent measurement todetermine if a criterion indicative of an intrusion of the monitoredframe is satisfied; and output an alarm activation signal when thecriterion is satisfied.

In one aspect of the disclosure, a method of protecting against impactbetween a vehicle and a physical structure, e.g., a wall, of a facilityhaving an opening or doorway for the vehicle to pass through, includesdefining a monitored area, e.g., a “monitored plane” as previouslydescribed or a “monitored frame” as previously described, relative tothe opening. The monitored area is defined by a plurality of baselinemeasurements, wherein each of the plurality of baseline measurements: 1)corresponds to a distance between a sensor spaced apart from astructure, e.g., wall edge or wall surface, that defines the opening andone of a plurality of virtual ends of the monitored area, and 2) isidentified by an angle parameter. The method also includes obtaining asubsequent measurement; evaluating the subsequent measurement relativeto a corresponding baseline measurement to determine if a criterionindicative of an intrusion of the monitored area is satisfied; andactivating an alarm when the criterion is satisfied.

In another aspect of the disclosure, a system for protecting againstimpact between a vehicle and a physical structure of a facility havingan opening or doorway for the vehicle to pass through includes ameasurement module and a detection module. The measurement module isconfigured to be spaced apart from a structure, e.g., wall edge or wallsurface, that defines the opening. The measurement module is furtherconfigured to rotate relative to the structure, and obtain a pluralityof measurements, wherein each of the plurality of measurementscorresponds to a distance from the measurement module.

The detection module is coupled to the measurement module and comprisesa definition module that defines a monitored area, e.g., a “monitoredplane” or a “monitored frame”, relative to the structure. The monitoredarea is defined by a plurality of baseline measurements, wherein each ofthe plurality of baseline measurements: 1) corresponds to a distancebetween the measurement module and one of a plurality of virtual ends ofthe monitored area, and 2) is identified by an angle parameter. Thedetection module is configured to obtain a subsequent measurement fromthe measurement module; associate an angle parameter with the subsequentmeasurement; evaluate the subsequent measurement relative to acorresponding baseline measurement having a same angle parameter todetermine if a criterion indicative of an intrusion of the monitoredarea is satisfied; and output an alarm activation signal when thecriterion is satisfied.

In one aspect of the disclosure, a method of protecting against impactbetween a vehicle and a facility configured to house the vehicleincludes automatically entering a protection system into a learningmode. The learning mode may be entered by detecting at a first sensor, asignal transmitted by a second sensor associated with a supplementalvehicle configured to couple with the vehicle and move the vehiclerelative to the facility, and responsive to detecting the signal,outputting a control signal that causes the protection system to enterthe learning mode. The method also includes creating a first monitoredplane relative to a first physical surface of the facility while in thelearning mode. The first monitored plane is defined by a plurality ofbaseline measurements. Each baseline measurement corresponds to adistance between a sensor spaced apart from the first physical surfaceand an object impeding a beam transmitted by the sensor, and isidentified by an angle parameter. The method further includes obtainingsubsequent measurements of the plurality of baseline measurements; andevaluating one or more subsequent measurements relative to correspondingone or more baseline measurements to determine if a criterion indicativeof an intrusion of the first monitored plane is satisfied.

In another aspect of the disclosure, a system for protecting againstimpact between a vehicle and a facility configured to house the vehicle,includes a measurement module, a learning module, and a detectionmodule. The measurement module is adapted to be spaced apart from afirst physical surface of the facility and is configured to rotaterelative to the first physical surface, and obtain a plurality ofmeasurements, wherein each measurement corresponds to a distance betweenthe measurement module and an object impeding a beam transmitted by themeasurement module.

The learning module is coupled to the measurement module and isconfigured to automatically enter a learning mode. While in the learningmode, the learning module is further configured to receive a pluralityof measurements from the measurement module corresponding to a pluralityof baseline measurements; associate an angle parameter with each of theplurality of baseline measurements; and create a first monitored planerelative to the first physical surface. The first monitored plane isdefined by the plurality of baseline measurements and correspondingangle parameters.

The detection module is coupled to the measurement module and isconfigured to automatically enter a detection mode after creation of thefirst monitored plane by the learning module. While in the detectionmode, the detection module is further configured to obtain one or moremeasurements from the measurement module, each corresponding to asubsequent measurement; associate an angle parameter with each of theone or more subsequent measurements; and evaluate the one or moresubsequent measurements relative to one or more baseline measurementshaving a same angle parameter to determine if a criteria indicative ofan intrusion of the first monitored plane is satisfied.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects systems and methods will now be presented in thedetailed description by way of example, and not by way of limitation,with reference to the accompanying drawings, wherein:

FIG. 1A is a schematic illustration of a hangar with the roof removed tomake visible an aircraft positioned in the hangar and areas of partialand full visual obstruction relative to an aircraft tug at the nose ofthe aircraft.

FIG. 1B is a schematic illustration of the hangar of FIG. 1A, whereinthe aircraft has been repositioned in a manner that results in an impactbetween the back surface or wall of the hangar and the tail of theaircraft.

FIG. 2 is a schematic illustration of a hangar with the roof removed tomake visible an aircraft positioned in the hangar and a protectionsystem having three veils or monitored planes that create protectedareas adjacent physical surfaces of the hangar.

FIG. 3 is an isometric illustration of a monitored plane that creates aprotected area adjacent a physical surface.

FIG. 4 is block diagram of a protection system including measurementmodules, a learning module, a detection module and alarm modules.

FIG. 5 is a plan view of a monitored plane relative to a pair ofphysical side surfaces, a floor and a ceiling, and showing a number ofbaseline measurements that define the monitored plane.

FIG. 6 is an isometric illustration of the monitored plane of FIG. 3breached by an object.

FIG. 7 is a plan view of a monitored plane and a cross-section of anobject breaching the monitored plane, and showing a number of subsequentmeasurements that indicate an intrusion of the monitored plane.

FIG. 8 is a flowchart of operation of the protection system of FIG. 4.

FIGS. 9A-9C are illustrations of one configuration of a hangar doorwayprotection system.

FIG. 10 is a block diagram of the hangar doorway protection system ofFIGS. 9A-9C.

FIG. 11 is a plan view of a monitored plane relative to an edge of aphysical structure of a hangar that includes a doorway, and showing anumber of baseline measurements that define the monitored plane.

FIG. 12 is a flowchart of operation of the doorway protection system ofFIG. 10.

FIGS. 13A-13C are illustrations of another configuration of a hangardoorway protection system.

FIG. 14 is a block diagram of the hangar doorway protection system ofFIGS. 13A-13C.

FIG. 15 is a plan view of a monitored plane relative to an edge of aphysical structure of a hangar that includes a doorway, and showing anumber of baseline measurements that define the monitored plane.

FIG. 16 is a flowchart of operation of the doorway protection system ofFIG. 14.

DETAILED DESCRIPTION

Disclosed herein is a protection system and method that protects againstimpact between a moving vehicle and a facility housing the vehicle. Forexample, the system and method may protect large physical surfaces orstructures, e.g., walls, of a hangar facility from accidental impact byan aircraft under tow. Using a network of sensors placed a distance froma wall, the protection system creates a corresponding network of virtualwalls or monitored planes, each spaced apart in a parallel arrangementwith a wall. Once this network of monitored planes is created, theprotection system uses the same network of sensors to monitor forpenetration or intrusion of a monitored place by an object, e.g. person,aircraft, ground support vehicle, etc. If a monitored plane ispenetrated, the system and method activate an aural and visual alarm tosignal the tug operator of a potential impact between the object and thephysical wall of the facility.

With reference to FIGS. 2 and 3, an example protection system 200installed in an aircraft hangar and configured in accordance with theconcepts disclosed herein includes three measurement modules 202 a, 202b, 202 c, a learning module 204, a detection module 206, and three alarmmodules 208 a, 208 b, 208 c. While the learning module 204 and detectionmodule 206 are shown separately, they may be embodied in a singlecontroller in the form of a microprocessor programmed to implement thefeatures of the protection system 200 described herein.

The modules of the protection system 200 are communicatively coupledtogether to allow information and data from the measurement modules 202a, 202 b, 202 c to reach the learning module 204 and the detectionmodule 206, and to allow control signals from learning module 204 toreach the measurement modules 202 a, 202 b, 202 c, and control signalsfrom the detection module 206 to reach the alarm modules 208 a, 208 b,208 c. The communication coupling may be wired or wireless.

As shown in FIG. 2, each of the measurement modules 202 a, 202 b, 202 cis associated with a respective physical surface of the hangar. Forexample, the first measurement module 202 a is associated with a firstsidewall 210 a of the hangar, the second measurement module 202 b isassociated with a second sidewall 210 b of the hangar, and the thirdmeasurement module 202 c is associated with a backwall 210 c of thehangar. The respective associations between the measurement modules 202a, 202 b, 202 c and the walls 210 a, 201 b, 210 c places the measurementmodules in a spaced apart relationship with the wall. To this end, eachmeasurement modules 202 a, 202 b, 202 c may be located on a pole 212 a,212 b, 212 c or rod that projects outward from the wall 210 a, 201 b,210 c.

Each of the measurement modules 202 a, 202 b, 202 c includes a sensor214 a, 214 b, 214 c that is configured to provide distance measurementsbetween itself and objects near the sensor. These objects may be, forexample, hangar surfaces including walls, the floor, the ceiling, orother structures within the hangar, such as tables, shelves, a parkedground support vehicle. Each of the measurement modules 202 a, 202 b,202 c also includes a rotation mechanism 216 a, 216 b, 216 c configuredto rotate the sensor 214 a, 214 b, 214 c at a particular rotation rate.To this end, each sensor 214 a, 214 b, 214 c is associated with a motor216 a, 216 b, 216 c that rotates under the control of the learningmodule 204 or the detection module 206. Rotation of the motor translatesto rotation of the sensor 214 a, 214 b, 214 c at the rotation rate.

Continuing with FIG. 2, each of the alarm modules 208 a, 208 b, 208 c isassociated with a respective physical surface of the hangar. Forexample, the first alarm module 208 a is associated with a firstsidewall 210 a of the hangar, the second alarm module 208 b isassociated with a second sidewall 210 b of the hangar, and the thirdalarm module 208 c is associated with a backwall 210 c of the hangar. Inan alternative configuration, the alarm modules 208 a, 208 b, 208 c areintegrated with a respective measurement modules 202 a, 202 b, 202 c.

With reference to FIGS. 2 and 3, during a learning phase of theprotection system 200, each of the sensors 214 a, 214 b, 214 c providesa set of baseline distance measurements to the learning module 204. Fromeach set of baseline measurements, the learning module 204 creates acorresponding monitored plane 218 a, 218 b, 218 c that is spaced apartfrom a respective surface 210 a, 210 b, 210 c. These monitored planes218 a, 218 b, 218 c are not physical in nature, but are instead virtualplanes, each of which is bound by its adjacent hangar surfaces 210 a,210 b, 210 c, 210 d, 210 e, the floor of the hangar and the ceiling ofthe hangar, and any other structures, e.g., tables, shelves, parkedground support vehicle, that are detected by the sensor. These monitoredplanes 218 a, 218 b, 218 c are defined by a set of baselinemeasurements. The distance between each surface 210 a, 210 b, 210 c andits respective monitored plane 218 a, 218 b, 218 c defines a protectedarea within the hangar. These distances are defined by the length of thepole 212 a, 212 b, 212 c to which the sensors 214 a, 214 b, 214 c areattached. The distance is typically in the range of 2 to 5 feet.

During a detection phase of the protection system 200, subsequentdistance measurements are provided to the detection module 206. Fromthese subsequent measurements, the detection module 206 determines if anobject has breached or crossed through a monitored plane 218 a, 218 b,218 c. If a breach or intrusion has occurred, the detection module 206outputs an activation signal to a corresponding alarm module 208 a, 208b, 208 c. The alarm module 208 a, 208 b, 208 c may be visual or aural innature. For example, the alarm module 208 a, 208 b, 208 c may includelights configured to flash and/or speakers configured to output an alarmsound.

Having thus described the configuration and operation of the protectionsystem 200 at a general level, a more detailed description follows.

With reference to FIG. 4, the protection system 200 includes one or moremeasurement modules 202 a, 202 b, 202 c, a learning module 204, adetection module 206, and one or more alarm modules 208 a, 208 b, 208 c.The number of measurement modules 202 a, 202 b, 202 c and alarm modules208 a, 208 b, 208 c corresponds to the number of surfaces of thefacility for which protection is sought. Thus, while only threemeasurement modules 202 a, 202 b, 202 c and alarm modules 208 a, 208 b,208 c for protecting three surfaces are shown in FIG. 4, more or lessmodules may be included in a protection system 200. The learning module204 and the detection module 206 may be embodied in a single controller402 having a memory 404 and a processor 406 programmed to implement thefeatures of the learning module 204 and the detection module 206 asdisclosed herein.

As described above, each of the measurement modules 202 a, 202 b, 202 cincludes a sensor 214 a, 214 b, 214 c that is configured to providedistance measurements between itself and objects, e.g., hangar surfaces,ceiling, floor, etc., near the sensor. Each sensor 214 a, 214 b, 214 cin turn, is associated with a motor 216 a, 216 b, 216 c that isconfigured to rotate at a particular rotation rate in accordance with acontrol signal output by the controller 402.

In one configuration, the sensor 214 a, 214 b, 214 c is a lightdetection and ranging (LIDAR) sensor that utilizes a pulsed laser lightand time of flight calculations to determine distance measurements. Anexample LIDAR sensor 214 a, 214 b, 214 c that may be employed by theprotection system 200 is a RPLIDAR A3 sensor manufactured by Slamtec. Inanother configuration, the sensor 214 a, 214 b, 214 c may be a RPLIDARA2 sensor, also manufactured by Slamtec. In yet another configuration,the sensor 214 a, 214 b, 214 c may be a TG30 LIDAR manufactured byYDLIDAR. In either configuration, the sensor 214 a, 214 b, 214 c isconfigured to output data 408 a, 408 b, 408 c corresponding to distancemeasurements at a programmable rate. For example, the sensors 214 a, 214b, 214 c may be programmed to output distance measurements 408 a, 408 b,408 c at a rate of one per one-thirty-six-hundredths (1/3600) of asecond, which equates to 3600 measurements per second.

The protection system may include one or more visual output devicesconfigured to provide visual cues to locations inside the facility andoutside the facility to thereby notify ground personnel of the status ofthe protection system. The visual output device allows ground personnelto determine if the protection system is up and running, or if it ismalfunctioning prior to moving an airplane into or out of the facility.The visual output device includes a light and a controller/detector thatcontrols the light.

In one configuration, the visual output devices may be a component ofone or more of the measurement modules 202 a, 202 b, 202 c. In otherconfigurations, the visual output devices may be associated withcomponents of the protection system other than the measurement modules202 a, 202 b, 202 c, such as the alarm modules 208 a, 208 b, 208 c.Alternatively, the visual output devices may be independent componentsof the protection system placed at locations both inside and outside thefacility that wirelessly communicate with other components of theprotection system, such as the sensor 214 a, 214 b, 214 c of themeasurement modules 202 a, 202 b, 202 c. In this case, the one or morevisual output devices may be located remote from all of the measurementmodules 202 a, 202 b, 202 c at a location that is more visible topersonnel.

The visual output device may be configured to activate the light in oneway, e.g., flash a red light, when the protection system is determinedto be malfunctioning, and in another way, e.g., steady green light, whenthe protection system is determined to be fully functional and up andrunning. A measurement modules 202 a, 202 b, 202 c of the protectionsystem is determined to be malfunctioning (meaning the system is notworking properly) or when the system enters a learning mode (meaning thesystem is functioning but is not yet ready to enter a detection mode).

The protection system may be determined to be malfunctioning if, forexample, a sensor 214 a, 214 b, 214 c of a measurement module 202 a, 202b, 202 c does not respond to the protection system controller. To thisend, each sensor 214 a, 214 b, 214 c may be configured to output asignal in response to a ping from the controller, and the visual outputdevice is configured to receive or detect these signals. In the case ofone or more separate visual output devices, each sensor 214 a, 214 b,214 c of a measurement module 202 a, 202 b, 202 c is configured tocommunicate wirelessly to the remotely located visual output device. Thevisual output device waits for an “I'm ok” signal from each sensor 214a, 214 b, 214 c. When the visual output device receives an “I'm ok”signal from all sensors 214 a, 214 b, 214 c, it may output anindication, e.g., steady green light, that the protection system isready. If the visual output device does not receive an “I'm ok” signalfrom all sensors 214 a, 214 b, 214 c, it may output an indication, e.g.,flashing red light, that the protection system is not ready.

The protection system may also be determined to be malfunctioning if thesystem fails to complete the learning mode (performed by the learningmodule 204 as described below) and thus fails to enter the detectionmode (performed by the detection module 206 as described below). To thisend, the system controller may be configured to output a signalcorresponding to the state of the learning mode, and the visual outputdevice is configured to receive or detect this signal and respondaccordingly. For example, in the case of a failure to complete thelearning mode, the visual output device may output an indication, e.g.,flashing red light, that the protection system is not up and running. Inthe case of a successful completion of the learning mode, the visualoutput device may output an indication, e.g., steady green light, thatthe protection system is up and running.

The learning module 204 receives distance measurements 408 a, 408 b, 408c from each of measurement modules 202 a, 202 b, 202 c and creates amonitored plane based on these measurements. As noted above, themonitored planes 218 a, 218 b, 218 c shown in FIGS. 2 and 3 are notphysical in nature, but instead are virtual planes, each having aperimeter defined by a set of distance measurements 408 a, 408 b, 408 creceived from a measurement module 202 a, 202 b, 202 c and acorresponding set of angle parameters that are assigned by the learningmodule 204. Thus, the monitored planes 218 a, 218 b, 218 c created bythe learning module 204 are structured as data sets 410 a, 410 b, 410 c,where each instance or data point in the data set is defined by adistance measurement 408 a, 408 b, 408 c and an angular measurement.These data sets 410 a, 410 b, 410 c may be stored in the memory 404 ofthe controller 402.

To determine the data points in these data sets 410 a, 410 b, 410 c, thelearning module 204 is configured to control rotation of the motor 216a, 216 b, 216 c of each respective measurement module 202 a, 202 b, 202c so its associated sensor rotates at a set rate. For example, thelearning module 204 may be programmed to output a control signal to eachmotor 216 a, 216 b, 216 c that causes the motor and it associated sensor214 a, 214 b, 214 c to rotate once, or 360 degrees, per second. Thus,rotating at a rate of 360 degrees per second and providing distancemeasurements 408 a, 408 b, 408 c at a rate of 3600 per second, themeasurement modules 202 a, 202 b, 202 c provide 3600 distancemeasurements for each 360 degree rotation of the sensor. In other words,the measurement modules 202 a, 202 b, 202 c provide a distancemeasurement 408 a, 408 b, 408 c every one-tenth of a degree of rotation.

Acquisition of a set of distance measurements for one physical surfaceis described further with reference to FIG. 5, which illustratesdistance measurements 408 b _(n) obtained by the measurement module 202b and sensor 214 b associated with the surface 210 b. While a largenumber, e.g., 3600, of such distance measurements per revolution may beobtained, for ease of illustration, a limited number of distances areshown in FIG. 5. Each of the distance measurements 408 b _(n)corresponds to distance between the sensor 214 b and an object in theline of sight of the laser pulse beam output by the sensor. Theseobjects in the line of sight may be, for example, a backwall 210 cadjacent to the surface 210 b, a floor 502, a ceiling 504, or a frontwall 210 e.

Assuming the sensor 214 b is directed to output its first laser pulsebeam at 0 degrees that aligns with 12 o'clock, and rotates onerevolution per second clockwise or 360 degrees back to 12 o'clockoutputting a laser pulse beam every one-thirty-six-hundredths (1/3600)of a second, the sensor will provide a first distance measurement 408 b₀ at 12 o'clock, a 900^(th) distance measurement 408 b ₉₀₀ 0.25 secondslater at 3 o'clock, a 1800^(th) distance measurement 408 b ₁₈₀₀ 0.5seconds later at 6 o'clock, a 2700^(th) distance measurement 408 b ₂₇₀₀0.75 seconds later at 9 o'clock and a 3600^(th) distance measurement 408b ₃₆₀₀ 1 seconds later at 12 o'clock.

Associated with each of these 3600 distance measurements is an angleparameter that identifies the angle at which the distance measurementwas obtained. For example, continuing with the example of FIG. 5, theparameter associated with the first distance measurement 408 b ₀ may be0 degrees, the parameter associated with the 900^(th) distancemeasurement 408 b ₉₀₀ may be 90 degrees, the parameter associated withthe 1800^(th) distance measurement 408 b ₁₈₀₀ may be 180 degrees, theparameter associated with the 2700^(th) distance measurement 408 b ₂₇₀₀may be 270 degrees, and the parameter associated with the 3600^(th)distance measurement 408 b ₃₆₀₀ may be 360 degrees.

The learning module 204 receives distance measurements 408 b from themeasurement module 202 b over a period of time or for a number ofrotations of the sensor 214 b, until a valid data set for the monitoredplane 218 b is obtained. To this end, the learning module 204 maycollect a set of distance measurements 408 b for each angularmeasurement or angle parameter and then apply a selection criterion orstatistical analysis to each set of distance measurements to derive avalid data point for each angular measurement.

In one configuration, the learning module 204 derives a valid data pointfor each angle by selecting the nearest or shortest distance measurement408 b from the set of distance measurements obtained for that angle, asthe valid distance measurement for that angle. For example, if a set offive distance measurements 408 b are obtained for each angle by fiverotations of the sensor 214 b, the learning module 204 compares the fivedistance measurements associated with each particular angle and selectsthe shortest distance as the valid distance measurement for thatparticular angle.

In another configuration, the learning module 204 derives a valid datapoint for each angle by averaging the distance measurements 408 bincluded in the set of distance measurements obtained for that angle.For example, if a set of five distance measurements 408 b are obtainedfor each angle by five rotations of the sensor 214 b, the learningmodule 204 calculates the average of the five distance measurementsassociated with each particular angle and defines the average as thevalid distance measurement for that particular angle.

In the example of FIG. 5, the resulting data set 410 b comprises 3600instances or data points, each defined by a distance measurement and anangle parameter. The data sets 410 a, 410 c for other physical surfaces210 a, 210 c are acquired in the same way. Portions of an example dataset are provided in Table 1.

TABLE 1 Angle parameter Distance measurement (degree of rotation)(millimeters) 90.0 5719 90.1 5719 90.2 5722 90.3 5737 90.4 5761 90.55783 90.6 5789 90.7 5796 90.8 5802 90.9 5805 . . . . . . 359.0 3729359.1 3694 359.2 3684 359.3 3684 359.4 3676 359.5 3669 359.6 3671 359.73664 359.8 3669 359.9 3661

It is noted that the shape, material, and reflectivity properties of thephysical surfaces, and the relative angle between the physical surfacesand the sensor 214 b laser beam may impact the ability of the sensor toobtain distance measurements 408 b at certain angles. As a result, validdistance measurements may not be obtainable at every angle in a data set410 b.

To address this scenario, the learning module 204 may be programmed todetermine a data set 410 b is valid when the learning module hasobtained valid distance measurements 408 b for a percentage of the totalnumber of possible data points. For example, the learning module 204 maydeclare a data set 410 b valid when the number of data points learned isbetween 85% and 95% of the total number of possible data points. In thecase of 3600 data points and a 90% threshold, the learning moduledeclares a data set valid when the module has learned 3240 data points.

To further address the scenario where valid distance measurements arenot obtainable at every angle in a data set 410 b, the learning module204 may be configured to derive these unobtainable distance measurementsbased on valid distance measurements included in the data set 410 b. Tothis end, the learning module 204 may derive an unobtainable distancemeasurement for a particular angle by locating valid distancemeasurements in the data set on either side of the particular angle andcalculating the average of these measurements. For example, withreference to Table 1, assuming the distance measurement for angle 359.5was unobtainable, the learning module 204 may locate the distancemeasurements for angles 359.4 and 359.6, calculate the average, andinsert that average into the data set 410 b as the distance measurementfor angle 359.5.

Once the data sets 410 a, 410 b, 410 c are established, the detectionmodule 206 begins to receive subsequent measurements 412 a, 412 b, 412 cfrom each of measurement modules 202 a, 202 b, 202 c and evaluates thesubsequent measurements relative to the baseline measurements. To thisend, the detection module 206 is configured to control rotation of themotor 216 a, 216 b, 216 c of each respective measurement module 202 a,202 b, 202 c so its associated sensor rotates at a set ratecorresponding to the same rate used to collect the baselinemeasurements. For example, the detection module 206 may be programmed tooutput a control signal to each motor 216 a, 216 b, 216 c that causesthe motor and it associated sensor 214 a, 214 b, 214 c to rotate 360degrees per second. Thus, rotating at a rate of 360 degrees per secondand providing distance measurements 412 a, 412 b, 412 c at a rate of3600 per second, the measurement modules 202 a, 202 b, 202 c provide3600 distance measurements for each 360 degree rotation of the sensor.In other words, the measurement modules 202 a, 202 b, 202 c provide adistance measurement 412 a, 412 b, 412 c every one-tenth of a degree ofrotation.

For each surface 210 a, 210 b, 210 c protected by a monitored plane 218a, 218 b, 218 c, the detection module 206 may evaluate subsequentmeasurements 412 a, 412 b, 412 c provided by the measurement module 202a, 202 b, 202 c associated with that surface relative to its baselinemeasurements 408 a, 408 b, 408 c to determine if an object haspenetrated or intruded the monitored plane. With reference to FIG. 6, anobject 602 is considered to breach or intrude a monitored plane 218 bwhen a part 604 or portion of it pass through the plane. The object 602may be, for example, a tip of an aircraft wing. The detection module 206detects such intrusions by comparing, in real time, one or moresubsequent measurements 412 a, 412 b, 412 c to corresponding baselinemeasurements 408 a, 408 b, 408 c to determine an intrusion state foreach monitored plane.

Acquisition of subsequent measurements for one physical surface isdescribed further with reference to FIG. 7, which illustrates subsequentdistance measurements 412 b _(n) obtained by the measurement module 202b and sensor 214 b associated with the surface 210 b. While a largenumber, e.g., 3600, of such distance measurements 412 b _(n) perrevolution may be obtained, for ease of illustration, a limited numberof distances are shown in FIG. 7. Each of the distance measurements 412b _(n) corresponds to a distance between the sensor 214 b and an objectin the line of sight of the laser pulse beam output by the sensor. Undernormal conditions, these objects in the line of sight would be the sameobjects that were present while the baseline measurements were obtained.Such objects include, for example, a backwall 210 c adjacent to thesurface 210 b, a floor 502, a ceiling 504, or a front wall 210 e. InFIG. 7, however, a part 604 of an object that was not present duringbaseline measuring is in the line of sight of a set of three laser pulsebeams output by the sensor 214 b. This causes the subsequentmeasurements 412 b _(x), 412 b _(y), 412 b _(z) to be different in valuefrom their corresponding baseline measurements 408 b _(x), 408 b _(y),408 b _(z) shown in FIG. 5. Based on these differences in measurementsthe detection module 206 may conclude that an intrusion of the monitoredplace 218 b has occurred.

In one configuration, the detection module 206 may conclude that anintrusion of a monitored plane 218 a, 218 b, 218 c occurred when any oneof the subsequent measurements 412 b _(x), 412 b _(y), 412 b _(z) isless than a value that is based on its corresponding baselinemeasurement 408 b _(x), 408 b _(y), 408 b _(z). In one embodiment thevalue is equal to the corresponding baseline measurement itself. In thiscase, an intrusion is concluded to occur when a subsequent measurements412 b _(x), 412 b _(y), 412 b _(z) is less than its correspondingbaseline measurement 408 b _(x), 408 b _(y), 408 b _(z). In anotherembodiment, the value is equal to the corresponding baseline measurementplus a buffer measurement. For example, the buffer measurement may be 5millimeters. Thus, in this case, an intrusion is concluded to occur whena subsequent measurements 412 b _(x), 412 b _(y), 412 b _(z) is lessthan its corresponding baseline measurement 408 b _(x), 408 b _(y), 408b _(z) plus 5 millimeters.

In another configuration, in order to reduce false alarms, the detectionmodule 206 may conclude that an intrusion of a monitored plane 218 a,218 b, 218 c occurred when a same subsequent measurement 412 b _(x), 412b _(y), 412 b _(z) is less than the value that is based on itscorresponding baseline measurement 408 b _(x), 408 b _(y), 408 b _(z)for a set number of consecutive measurements or over a period of time.For example, assuming a particular subsequent measurement 412 b _(x) isobtained once every second, then an intrusion state may be consideredpresent when three consecutive instances of that particular subsequentmeasurement 412 b _(x) are less than the value that is based on itscorresponding baseline measurement 408 b _(x).

In yet another configuration, in order to reduce false alarms, thedetection module 206 may conclude that an intrusion of a monitored planeoccurred when a threshold number of subsequent measurements 412 b, in aset of adjacent subsequent measurements agree that an intrusionoccurred. To this end, when the detection module 206 determines that afirst subsequent measurement 412 b _(x) indicates an intrusion, i.e.,the subsequent measurement is less than the value based on itscorresponding baseline measurement, the detection module determines ifone or more other subsequent measurements 412 b _(y), 412 b _(z)adjacent to the first subsequent measurement also indicate an intrusion.For example, the detection module 206 may evaluate five subsequentmeasurements 412 b adjacent to the first subsequent measurement 412 b_(x) and conclude that a detection occurred when at least three of thefive subsequent measurements 412 b also indicated an intrusion. In thiscase, adjacent subsequent measurements 412 b are measurements that areobtained one after the other, at different angles, after the firstsubsequent measurement 412 b _(x) that first indicated the intrusion.

FIG. 8 is a flowchart of a method of protecting against impact between amoving vehicle and a facility for housing the vehicle. The method may beperformed by the protection system of FIG. 4. The method comprises threegeneral sets of steps, each corresponding to an operation mode or stateof the protection system 200. These modes include an idle mode 802, alearning mode 804, and a detection mode 806.

In the idle mode 802, the system's controller 402 is powered on, but istypically not collecting or processing any data. The controller 402 issimply waiting for an input trigger to enter into another mode. An inputtrigger may result from operator activation of an operational switch orgraphical user interface button on the controller. In otherconfigurations, less reliant on operator input, an input trigger mayautomatically result from a detection of movement or motion within thefacility by a motion sensor. In one configuration, a sensor mounted on avehicle tug is wirelessly paired with a sensor associated with thefacility, e.g., on a wall of the facility. When the tug is powered on,the tug sensor is activated. When the tug and its associated tug sensormove within range of the facility sensor, the facility sensorautomatically causes the controller 402 to enter the learning mode,followed by the detection mode. When the tug and its associated sensormove out of range of the facility sensor, or when the tug and itsassociated sensor are powered off, the facility sensor outputs a signalthat automatically causes the controller 402 to return to the idle mode.This return to the idle mode may occur a pre-determined period of timeafter the tug and its associated sensor move out of range of thefacility sensor, or after the tug and its associated sensor are poweredoff. This automatic feature allows for the protection system to be inidle mode when it is not needed, thereby reducing false detections. Italso helps to eliminate operator error in that no operational switch isrequired to be turned on by an operator for the protection system towork.

In the learning mode 804, the system's sensors rotate about a plane ofrotation to obtain data points corresponding to distances between thesensor and walls, ceilings, floors, and any other object in the plane.The protection system 200 may be configured to enter the learning mode804 upon the occurrence of an input trigger as described above. In oneconfiguration, the protection system 200 remains in the learning mode804 until it has learned a pre-determined and pre-programed percentageof data points, where each data point is defined by an angle parameterand a distance measurement. The learning mode 804 results in a baselinedata set of data points to compare with subsequent data points compiledduring the detection mode 806. The protection system 200 mayautomatically switch to the detection mode 806 from learning mode 804when it has compiled the required amount of data points in the learningmode.

As noted above, the shape, material, and reflectivity properties of thephysical surfaces that the sensor is detecting, and the relative anglebetween these surfaces and the senor laser beam, all play a role in howlong (or how many rotational sweeps of the sensor) it takes to build avalid baseline set of data points. Since the protection system 200 isutilizing measurements at 0.1 degree increments, there are a lot of datapoints to compile. The sensor may not be able to learn 100% of the datain a reasonable amount of time. In some cases, distance measurements atcertain degrees may not be detected by the sensor at all due to shape,material, angle and reflectivity properties of the surfaces. Therefore,the protection system 200 may be programmed to enter the detection mode806 when it has learned a percentage of the total number of possibledata points. For example, the protection system 200 may enter thedetection mode 806 when the number of data points learned is between 85%and 95% of the total number of possible data points. In the case of 3600data points and a 90% threshold, the protection system 200 enters thedetection mode 806 when the system has learned 3240 data points.

Regarding missing data points, while in the detection mode 806, theprotection system 200 may continue to attempt to learn these data pointsand add them to the baseline set of data points as they are learned.Accordingly, the sensors may continue to detect for distancemeasurements for the missing data points. Alternatively, the protectionsystem 200 may derive the missing data points based on current datapoints adjacent to the missing data point. For example, a missingdistance measurement for an angle may be derived by calculating theaverage of one or more distance measurements on one or both sides of theangle.

In the detection mode 806, the system's sensors obtain subsequentdistance measurements and compares them to corresponding baselinedistance measurements used to compile the baseline data points inlearning mode 804. The controller 402 looks for any distance that iscloser to the sensor than that which was recorded in the learning mode.If a new object enters the sensor's plane of rotation, the controller402 detects that the subsequent distance at an angle is closer than thecorresponding baseline distance at the same angle. The system'scontroller 402 may then send a signal for the attached alarms toactivate, thus letting the tug operator know of a new intrusion into theplane.

Having generally described the three modes of operation, a more detaileddescription follows, wherein operation of the protection system 200 iswithin the context of a moving vehicle corresponding to an aircraftunder tow and a facility corresponding to an aircraft hangar. Theprotection system 200, however, may operate in any other environmentsinvolving moving vehicles and related housing or storage facilities.

Continuing with FIG. 8, in the idle mode 802, at block 808 thecontroller 402 of the protection system 200 enters a power on state.This may occur through user operation, e.g., manually activating a powerswitch or button on a user interface 414, or automatically in accordancewith a schedule or occurrence of an event, e.g. turn on at a particulartime of day or when a door of the hangar opens.

At block 810, upon being turned on, the controller 402 activates each ofits associated measurement modules 202 a, 202 b, 202 c. To this end, thecontroller 402 sends a control signal to each of the sensors 214 a, 214b, 214 c and the motors 216 a, 216 b, 216 c causing each to turned on.At this time, the sensors 214 a, 214 b, 214 c begin to output laserpulses and the motors 216 a, 216 b, 216 c begin to rotate the sensors.

At block 812, the controller 402 detects for a learning mode trigger. Alearning mode trigger may correspond to a user operation, e.g., manuallyactivating a learning switch or on-screen button on the user interface414, or an occurrence of an event, e.g. turn on of the controller 402 ordetection of movement or motion within the hangar. If a learning modetrigger is detected at block 812, the protection system 200 enters thelearning mode 804; otherwise the protection system remains in the idlemode 802.

While in the learning mode 804, the protection system 200 creates one ormore monitored planes 218 a, 218 b, 218 c each relative to a physicalsurface 210 a, 210 b, 210 c of the hangar. To this end, at block 814,each sensor 214 a, 214 b, 214 c obtains baseline measurements 408 a, 408b, 408 c while rotating about an axis perpendicular to its respectivephysical surface at a rotation rate. The physical surfaces 210 a, 210 b,210 c may be walls of the hangar. As described above with reference toFIGS. 4 and 5, each of these baseline measurements 408 a, 408 b, 408 ccorresponds to a distance between the sensor 214 a, 214 b, 214 c and anobject impeding a beam transmitted by the sensor. These measurements 408a, 408 b, 408 c may be obtained every n degrees of rotation.

As also described above with reference to FIGS. 4 and 5, an objectimpeding a beam transmitted by a sensor 214 a, 214 b, 214 c may beanother structure of the facility, such as a second physical surfaceadjacent the first physical surface, a floor adjacent the first physicalsurface, or a ceiling adjacent the first physical surface. The object,however, is not necessarily a structure of the facility and may be, forexample, a table, a cart, a shelf, etc. As also described above withreference to FIGS. 2 and 3, the sensor 214 a, 214 b, 214 c is spacedapart from its respective physical surface such that the sensor beamstravels along a path that does not impact its respective physicalsurface. For example, the sensor may be positioned relative to thephysical surface so that the beam path is generally parallel to thefirst physical surface.

Returning to FIG. 8, the measurement modules 202 a, 202 b, 202 cprovides the baseline measurements to the learning module 204. At block816, the learning module 204 creates a corresponding monitored plane 218a, 218 b, 218 c based on each set of baseline measurements. As describedabove with reference to FIG. 5, each monitored plane 218 a, 218 b, 218 cis defined by a data set 410 a, 410 b, 410 c that comprises instances ofdata points, where each data point includes one of the plurality ofbaseline measurements 408 a, 408 b, 408 c and its corresponding angleparameter. These data set 410 a, 410 b, 410 c basically define theperimeter of the monitored planes 218 a, 218 b, 218 c.

At block 818, the controller 402 detects for a detection mode trigger. Adetection mode trigger may correspond to a user operation, e.g.,manually activating a detection switch or on-screen button on the userinterface 414, or an occurrence of an event, e.g. completion of thelearning mode 804. If a detection mode trigger is detected, theprotection system 200 enters the detection mode 806.

While in the detection mode 806, the protection system 200 obtainssubsequent measurements of the plurality of baseline measurements. Tothis end, at block 820, each sensor 214 a, 214 b, 214 c obtainssubsequent measurements 412 a, 412 b, 412 c, while rotating about anaxis perpendicular to the first physical surface at a rotation rate. Asdescribed above with reference to FIGS. 4 and 7, each of thesesubsequent measurements 412 a, 412 b, 412 c corresponds to a distancebetween the sensor 214 a, 214 b, 214 c and an object impeding a beamtransmitted by the sensor. These measurements are obtained every ndegrees of rotation.

At block 822, the detection module 206, evaluates one or more subsequentmeasurements 412 a, 412 b, 412 c relative to corresponding one or morebaseline measurements 408 a, 408 b, 408 c to determine if a criterionindicative of an intrusion of a monitored plane 218 a, 218 b, 218 c issatisfied. For example, the criterion may be satisfied when each of theone or more subsequent measurements 412 a, 412 b, 412 c is less than avalue that is based on its corresponding baseline measurement 408 a, 408b, 408 c. This value may be equal to one of the corresponding baselinemeasurement itself, or the corresponding baseline measurement plus abuffer measurement. Furthermore, the one or more subsequent measurementscomprises a plurality of subsequent measurements that are obtained insequence.

At block 824, if an intrusion is not present, the process returns toblock 822 where the detection module 206 continues to evaluate one ormore subsequent measurements 412 a, 412 b, 412 c relative tocorresponding one or more baseline measurements 408 a, 408 b, 408 c todetermine if the criterion indicative of an intrusion of a monitoredplane 218 a, 218 b, 218 c is satisfied. If, however, an intrusion stateis present at block 824, the process proceeds to block 826, where thedetection module 206 activates an alarm. To this end, the detectionmodule 206 outputs a control signal to the alarm module 208 a, 208 b,208 c associated with the monitored plane 218 a, 218 b, 218 c that wasbreached to activate the alarm.

Upon activation of an alarm module 208 a, 208 b, 208 c, the processreturns to block 822, where the detection module 206 continues toevaluate one or more subsequent measurements 412 a, 412 b, 412 crelative to corresponding one or more baseline measurements 408 a, 408b, 408 c to determine if the criterion indicative of an intrusion of amonitored plane 218 a, 218 b, 218 c is satisfied. To this end, thedetection module 206 monitors the existing breach to determine if thebreach persists, while also monitoring for new breaches. Regarding theexisting breach, if current subsequent measurements 412 a, 412 b, 412 ccause the detection module 206 to determine that the intrusion criterionis no longer satisfied, the process proceeds to block 828, where thepreviously activated alarm is deactivated.

At block 830, protection system 200 may return to the idle mode 802 upona user operation, e.g., manually activating an idle switch or on-screenbutton on the user interface 414, or an occurrence of an event, e.g.after a pre-determined period of time or after output of a controlsignal by a facility sensor. For example, as described above, when a tugand its associated sensor move out of range of a facility sensor, orwhen a tug and its associated sensor are powered off, the facilitysensor outputs a signal that automatically causes the controller 402 toreturn to the idle mode.

Returning to FIG. 4, the controller 402 of the protection system 200 mayinclude one or more processors 406 configured to access and executecomputer-executable instructions stored in at least one memory 404. Theprocessor 406 may be implemented as appropriate in hardware, software,firmware, or combinations thereof. Software or firmware implementationsof the processor 406 may include computer-executable ormachine-executable instructions written in any suitable programminglanguage to perform the various functions described herein. Theprocessor 406 may include, without limitation, a central processing unit(CPU), a digital signal processor (DSP), a reduced instruction setcomputer (RISC) processor, a complex instruction set computer (CISC)processor, a microprocessor, a microcontroller, a field programmablegate array (FPGA), a System-on-a-Chip (SOC), or any combination thereof.The controller 402 may also include a chipset (not shown) forcontrolling communications between the processor 406 and one or more ofthe other components of the controller. The processor 406 may alsoinclude one or more application-specific integrated circuits (ASICs) orapplication-specific standard products (ASSPs) for handling specificdata processing functions or tasks.

The memory 404 may include, but is not limited to, random access memory(RAM), flash RAM, magnetic media storage, optical media storage, and soforth. The memory 404 may include volatile memory configured to storeinformation when supplied with power and/or non-volatile memoryconfigured to store information even when not supplied with power. Thememory 404 may store various program modules, application programs, andso forth that may include computer-executable instructions that uponexecution by the processor 406 may cause various operations to beperformed. The memory 404 may further store a variety of datamanipulated and/or generated during execution of computer-executableinstructions by the processor 406.

The controller 402 may further include one or more network interfaces416 that may facilitate communication between the controller and one ormore measurement modules 202 a, 202 b, 202 c and one or more alarmmodules 208 s, 208 b, 208 c using any suitable communications standard.For example, a LAN interface may implement protocols and/or algorithmsthat comply with various communication standards of the Institute ofElectrical and Electronics Engineers (IEEE), such as IEEE 802.11, whilea cellular network interface implement protocols and/or algorithms thatcomply with various communication standards of the Third GenerationPartnership Project (3GPP) and 3GPP2, such as 3G and 4G (Long TermEvolution), and of the Next Generation Mobile Networks (NGMN) Alliance,such as 5G.

The memory 404 may store various program modules, application programs,and so forth that may include computer-executable instructions that uponexecution by the processor 406 may cause various operations to beperformed. For example, the memory 404 may include an operating systemmodule (O/S) that may be configured to manage hardware resources such asthe network interface 416 and provide various services to applicationsexecuting on the controller 402.

The memory 404 stores additional program modules such as the learningmodule 204 and the detection module 206, each of which includesfunctions in the form of logic and rules that respectively support andenable the learning and detection functions described above withreference to FIGS. 2-8. Although illustrated as separate modules in FIG.4, one or more of the modules may be a part of or a submodule of anothermodule.

The controller 402 and modules 204, 206 disclosed herein may beimplemented in hardware or software that is executed on a hardwareplatform. The hardware or hardware platform may be a general purposeprocessor, a digital signal processor (DSP), an application specificintegrated circuit (ASIC), a field programmable gate array (FPGA) orother programmable logic component, discrete gate or transistor logic,discrete hardware components, or any combination thereof, or any othersuitable component designed to perform the functions described herein. Ageneral-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing components, e.g., acombination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSP,or any other such configuration.

Software shall be construed broadly to mean instructions, instructionsets, code, code segments, program code, programs, subprograms, softwaremodules, applications, software applications, software packages,routines, subroutines, objects, executables, threads of execution,procedures, functions, etc., whether referred to as software, firmware,middleware, microcode, hardware description language, or otherwise. Thesoftware may reside on a computer-readable medium. A computer-readablemedium may include, by way of example, a smart card, a flash memorydevice (e.g., card, stick, key drive), random access memory (RAM), readonly memory (ROM), programmable ROM (PROM), erasable PROM (EPROM),electrically erasable PROM (EEPROM), a general register, or any othersuitable non-transitory medium for storing software.

Disclosed herein are doorway protection systems and methods thatprotects against impact between a moving vehicle and a physicalstructure, e.g., wall, of a facility that has an entryway or doorwaythrough which vehicles enter and exit the facility. For example, thesystem and method may protect the physical structure, e.g., wall, aroundthe doorway of a hangar facility from accidental impact by an aircraftunder tow. In one configuration, one or more monitored planes aredefined relative to the sides and top of the entryway. A network ofsensors placed a distance from the sides and top monitor for penetrationor intrusion of the monitored plane by an object, e.g. aircraft, groundsupport vehicle, etc. If a monitored plane is penetrated, the system andmethod activate an aural and visual alarm to signal the tug operator ofa potential impact between the object and the entryway wall of thefacility. In another configuration, a pair of monitored frames aredefined relative to the entryway structure, one relative to the outsidesurface of the structure and the other relative to the inside surface ofthe structure. A pair of sensors, each placed a distance from arespective one of the inside surface and outside surface, monitors forpenetration or intrusion of the monitored frame by an object, e.g.aircraft, ground support vehicle, etc. If a monitored frame ispenetrated, the system and method activate an aural and visual alarm tosignal the tug operator of a potential impact between the object and theentryway wall of the facility.

With reference to FIGS. 9A-9C, in one configuration, a doorwayprotection system 900 installed in an aircraft hangar and configured inaccordance with the concepts disclosed herein includes three measurementmodules 902 a, 902 b, 902 c, a detection module 904 with threepre-defined monitored plane data sets 906 a, 906 b, 906 c, and threealarm modules 908 a, 908 b, 908 c. Each measurement module 902 a, 902 b,902 c is similar to those described above with reference to FIGS. 2-4and includes a sensor 914 a, 914 b, 914 c mounted on a rotational motor.

The modules of the doorway protection system 900 are communicativelycoupled together to allow information and data from the measurementmodules 902 a, 902 b, 902 c to reach the detection module 904, and toallow control signals from the detection module 904 to reach the alarmmodules 908 a, 908 b, 908 c. The communication coupling may be wired orwireless.

Each of the measurement modules 902 a, 902 b, 902 c is associated with arespective edge of a physical structure 901, e.g., a doorway wall, thatdefines a doorway 903 of the hangar. For example, the first measurementmodule 902 a is associated with a first side edge 910 a of the doorwaywall 901, the second measurement module 902 b is associated with the topedge 910 b of the doorway wall, and the third measurement module 902 cis associated with a second side edge 910 c of the doorway wall. Therespective associations between the measurement modules 902 a, 902 b,902 c and the edges 910 a, 901 b, 910 c places the measurement modulesin a spaced apart relationship with the edge. To this end, eachmeasurement modules 902 a, 902 b, 902 c may be located on a pole 912 a,912 b, 912 c or rod that projects outward from the edge 910 a, 910 b,910 c.

Each of the alarm modules 908 a, 908 b, 908 c may be associated with arespective physical structure of the hangar in a vicinity of an edge ofthe doorway wall 901. For example, the first alarm module 908 a may beassociated with a surface of the doorway wall 901 near the first sideedge 910 a of the doorway, the second alarm module 908 b may beassociated with a surface of the doorway wall near the top edge 910 b ofthe doorway, and the third alarm module 908 c may be associated with asurface of the doorway wall 901 near the second side edge 910 c of thedoorway. In an alternative configuration, the alarm modules 908 a, 908b, 908 c may be integrated with a respective measurement modules 902 a,902 b, 902 c.

With continued reference to FIGS. 9A-9C, in one configuration thedetection module 904 defines a monitored plane 918 a, 918 b, 918 c foreach respective edge 910 a, 910 b, 910 c of the doorway wall 901. Thesemonitored planes 918 a, 918 b, 918 c are not physical in nature, but areinstead virtual planes, each of which is spaced apart from itsrespective edge 910 a, 910 b, 910 c and extends a distance, e.g.,between 1 and 6 feet, into the hangar and out of the hangar. Thesemonitored planes 918 a, 918 b, 918 c are defined by monitored plane datasets 906 a, 906 b, 906 c that include a number of baseline measurements,each corresponding to a distance between a sensor 914 a, 914 b, 914 cspaced apart from a respective edge 910 a, 910 b, 910 c and a virtualend of a monitored plane. The area size of each monitored plane 918 a,918 b, 918 c defines a protected area around its respective edge 910 a,910 b, 910 c. The distance between each edge 910 a, 910 b, 910 c and itsrespective monitored plane 918 a, 918 b, 918 c defines a protected spacefor the doorway wall 901. These distances are defined by the length ofthe pole 912 a, 912 b, 912 c to which the sensors 914 a, 914 b, 914 care attached. The distance is typically in the range of 1 to 6 feet.

During a detection phase of the doorway protection system 900,subsequent distance measurements are obtained by the measurement modules902 a, 902 b, 902 c and provided to the detection module 906. From thesesubsequent measurements, the detection module 906 determines if anobject has breached or crossed through a monitored plane 918 a, 918 b,918 c and into a protected space of the doorway wall 901. If a breach orintrusion has occurred, the detection module 906 outputs an activationsignal to a corresponding alarm module 908 a, 908 b, 908 c. The alarmmodule 908 a, 908 b, 908 c may be visual or aural in nature. Forexample, the alarm module 908 a, 908 b, 908 c may include lightsconfigured to flash and/or speakers configured to output an alarm sound.

Having thus described the configuration and operation of the doorwayprotection system 900 at a general level, a more detailed descriptionfollows.

With reference to FIG. 10, the doorway protection system 900 includesone or more measurement modules 902 a, 902 b, 902 c, a detection module904 including one or more monitored plane data sets 906 a, 906 b, 906 c,and one or more alarm modules 908 a, 908 b, 908 c. The number ofmeasurement modules 902 a, 902 b, 902 c and alarm modules 908 a, 908 b,908 c typically corresponds to the number of edges of the doorway wall901 for which protection is sought, which is usually three. Thedetection module 904 may be embodied in a controller 1002 having amemory 1004 and a processor 1006 programmed to implement the features ofthe detection module 904 as disclosed herein.

As described above, each of the measurement modules 902 a, 902 b, 902 cincludes a sensor 914 a, 914 b, 914 c that is configured to providedistance measurements between itself and objects, e.g., aircraft wing,etc., near the sensor. Each sensor 914 a, 914 b, 914 c in turn, isassociated with a motor 916 a, 916 b, 916 c that is configured to rotateat a particular rotation rate in accordance with a control signal outputby the controller 1002.

In one configuration, the sensor 914 a, 914 b, 914 c is a lightdetection and ranging (LIDAR) sensor that utilizes a pulsed laser lightand time of flight calculations to determine distance measurements. Anexample LIDAR sensor 914 a, 914 b, 914 c that may be employed by thedoorway protection system 900 is a RPLIDAR A3 sensor manufactured bySlamtec. In another configuration, the sensor 914 a, 914 b, 914 c may bea RPLIDAR A29 sensor, also manufactured by Slamtec. In yet anotherconfiguration, the sensor 914 a, 914 b, 914 c may be a TG30 LIDARmanufactured by YDLIDAR. In either configuration, the sensor 914 a, 914b, 914 c is configured to output data 1012 a, 1012 b, 1012 ccorresponding to distance measurements at a programmable rate. Forexample, the sensors 914 a, 914 b, 914 c may be programmed to outputdistance measurements 1012 a, 1012 b, 1012 c at a rate of one perone-thirty-six-hundredths (1/3600) of a second, which equates to 3600measurements per second.

The monitored plane data sets 906 a, 906 b, 906 c include a list ofbaseline measurements that define a corresponding one of the monitoredplanes 918 a, 918 b, 918 c. To this end, a baseline measurement isprovided for each degree of rotation at which a measurement module 902a, 902 b, 902 c is configured to obtain a measurement. Each baselinemeasurement includes 1) a distance between a measurement module and oneof a plurality of virtual ends of the monitored plane, and 2) isidentified by an angle parameter.

With reference to FIG. 11, a plane corresponding to the monitored plane918 c shown in FIG. 9A includes four virtual ends 1102, 1104, 1106,1108. The monitored plane data set 906 c for this monitored plane 918 cincludes a baseline measurement 1110 for each of one-tenth degree ofrotation of the measurement module 902 c. For clarity of illustration,only four baseline measurements 1110 are shown in FIG. 11. Thesemeasurements include:

1) a baseline measurement 1110 c ₉₀₀ corresponding to a 90 degreerotation point of the measurement module 902 c, which is set to a valueequal to the distance between the measurement module and the firstvirtual end 1102 of the monitored plane 918 c;

2) a baseline measurement 1110 c ₁₈₀₀ corresponding to a 180 degreerotation point of the measurement module 902 c, which is set to a valueequal to the distance between the measurement module and the secondvirtual end 1104 of the monitored plane 918 c;

3) a baseline measurement 1110 c 2 ₇₀₀ corresponding to a 270 degreerotation point of the measurement module 902 c, which is set to a valueequal to the distance between the measurement module and the thirdvirtual end 1106 of the monitored plane 918 c; and

4) a baseline measurement 1110 c ₃₆₀₀ corresponding to a 360 degreerotation point of the measurement module 902 c, which is set to a valueequal to the distance between the measurement module and the fourthvirtual end 1108 of the monitored plane 918 c.

In the example of FIG. 11, the monitored plane data set 906 c comprises3600 instances or data points, each defined by a distance measurementand an angle parameter. The monitored plane data sets 906 a, 906 b aresimilarly defined. Portions of an example monitored plane data set 906 care provided in Table 2.

TABLE 2 Angle parameter Distance measurement (degree of rotation)(millimeters) 180.0 610 180.1 610 180.2 611 180.3 611 180.4 612 180.5612 180.6 613 180.7 613 180.8 614 180.9 614 . . . . . . 270.0 3600 270.13600 270.2 3605 270.3 3605 270.4 3610 270.5 3610 270.6 3615 270.7 3615270.8 3620 270.9 3620

The detection module 904 receives subsequent measurements 1012 a, 1012b, 1012 c from each of measurement modules 902 a, 902 b, 902 c andevaluates the subsequent measurements relative to the baselinemeasurements. To this end, the detection module 904 is configured tocontrol rotation of the motor 916 a, 916 b, 916 c of each respectivemeasurement module 902 a, 902 b, 902 c so its associated sensor rotatesat a set rate corresponding to the same rate used to define the baselinemeasurements. For example, the detection module 904 may be programmed tooutput a control signal to each motor 916 a, 916 b, 916 c that causesthe motor and it associated sensor 914 a, 914 b, 914 c to rotate 360degrees per second. Thus, rotating at a rate of 360 degrees per secondand providing distance measurements 1012 a, 1012 b, 1012 c at a rate of3600 per second, the measurement modules 902 a, 902 b, 902 c provide3600 distance measurements for each 360 degree rotation of the sensor.In other words, the measurement modules 902 a, 902 b, 902 c provide adistance measurement 1012 a, 1012 b, 1012 c every one-tenth of a degreeof rotation.

For each doorway edge 910 a, 910 b, 910 c protected by a monitored plane918 a, 918 b, 918 c, the detection module 904 may evaluate subsequentdistance measurements 1012 a, 1012 b, 1012 c provided by the measurementmodule 902 a, 902 b, 902 c associated with that surface relative to itscorresponding baseline measurement included in the relative monitoredplane data set 906 a, 906 b, 906 c to determine if an object haspenetrated or intruded the monitored plane. For example, as describedabove with reference to FIG. 6, an object 602 may be considered tobreach or intrude a monitored plane 218 b when a part 604 or portion ofit pass through the plane. The object 602 may be, for example, a tip ofan aircraft wing. Likewise, with reference to FIGS. 9B, 9C and 11, anobject 905 may be considered to breach or intrude a monitored plane 918a, 918 b, 918 c when a part or portion of it passes through the plane.The detection module 904 detects such intrusions by comparing, in realtime, one or more subsequent measurements 1012 a, 1012 b, 1012 c tocorresponding baseline measurements to determine an intrusion state foreach monitored plane. The detection module 904 may conclude that anintrusion of a monitored plane 918 a, 918 b, 918 c occurred inaccordance with any one of the various configurations described abovewith reference to FIG. 7, the details of which are not repeated at thisstage of the disclosure.

FIG. 12 is a flowchart of a method of protecting against impact betweena vehicle and a physical structure, e.g., doorway wall, of a facilitythat has opening or doorway for the vehicle to pass through. The methodmay be performed by the doorway protection system 900 of FIGS. 9A-9C and10.

At block 1202, a monitored plane 918 a, 918 b, 918 c is defined for atleast one edge 910 a, 901 b, 910 c of the physical structure 901, e.g.,a doorway wall, that includes the doorway 903. The monitored plane isdefined by a plurality of baseline. For example, with reference to FIG.11, monitored plane 918 c is defined by a plurality of baselinemeasurements 1110 c, each of which corresponds to a distance between asensor 914 c spaced apart from the edge and one of a plurality ofvirtual ends 1102, 1104, 1106, 1108 of the monitored plane, and isidentified by an angle parameter. Returning to FIGS. 9A-9C, each of themonitored planes 918 a, 918 b, 918 c may be defined by a correspondingmonitored plane data set 906 a, 906 b, 906 c that includes the pluralityof baseline measurements and is stored in a detection module 904 of thedoorway protection system 900.

In one configuration, and continuing with the monitored plane 918 cshown in FIG. 11, the angle parameter identifying a particular baselinemeasurement 1110 c is a n degree of rotation of the sensor 914 c.Returning again to FIGS. 9A-9C, the virtual ends 1102, 1104, 1106, 1108of a monitored plane 918 a, 918 b, 918 c include an inside end 920 atthe interior of the facility that is spaced a distance from an insidesurface 922 of the doorway wall 901, and an outside end 924 at theexterior of the facility that is spaced a distance from an outsidesurface 926 of the doorway wall. The distances between these ends 920,924 and their respective surfaces 922, 926 may be in the range of 1 to 6feet.

Regarding the plurality of edges of the doorway wall 901 that define thedoorway 903, these edges may include a first side edge 910 a, a secondside edge 910 c opposite the first side edge, and a top edge 910 bspanning the first side edge and the second side edge. In this case, theplurality of virtual ends of the vertical monitored plane 918 a, 918 cfor either of the first side edge 910 a or the second side edge 910 cfurther comprises a top end 928 a, 928 c, 1108 spaced a distance fromthe top edge 910 b of the opening, and the plurality of virtual ends forthe horizontal monitored plane 918 b for the top edge 910 b furthercomprises a first end 930 b a distance from the first side edge 910 aand a second end 932 b a distance from the second side edge 910 c. Thedistances between these ends 928 a, 928 c, 930 b, 932 b and theirrespective edges 910 a, 910 b, 910 c may be in the range of 1 to 3 feet.

Returning to FIG. 12, at block 1204, a subsequent measurement isobtained. To this end, a sensor 914 a, 914 b, 914 c is rotated relativeto the edge 910 a, 901 b, 910 c, and a plurality of subsequentmeasurements are obtained. For example, a subsequent measurement may beobtained at every n degree of rotation of the sensor.

At block 1206, the subsequent measurement is evaluated relative to acorresponding baseline measurement to determine if a criterionindicative of an intrusion of the monitored plane is satisfied. In oneconfiguration, the criterion is satisfied when a subsequent measurementat an n degree of rotation is less than a value that is based on thecorresponding baseline measurement identified by the n degree ofrotation. For example, with reference to FIGS. 9B, 9C, and 11, if anobject 905, e.g., an end of an aircraft wing, enters into a monitoredplane 918 c, a subsequent measurement 1110 c _(x) obtained by the sensor914 c at an n degree of rotation that aligns the beam of the senor withthe object will result in a subsequent measurement less than thebaseline measurement corresponding to that n degree of rotation.

At block 1208, an alarm associated with an alarm module 908 a, 908 b,908 c is activated when the criterion is satisfied. Continuing with themonitored plane 918 c of FIG. 11, after an alarm is activated, anothermeasurement of the subsequent measurement 1110 c _(x) that triggered thealarm is obtained and evaluated relative to the corresponding baselinemeasurement to determine if the criterion indicative of the intrusion ofthe monitored plane 918 c is no longer satisfied. At block 1210, thealarm is deactivated when the criterion is no longer satisfied. Theseother measurement of the subsequent measurement 1110 c _(x) may beobtained during each rotation of the sensor 914 c.

With reference to FIGS. 13A-13C, in another one configuration, a doorwayprotection system 1300 installed in an aircraft hangar and configured inaccordance with the concepts disclosed herein includes two measurementmodules 1302 a, 1302 b, a detection module 1304 with two pre-definedmonitored frame data sets 1306 a, 1306 b, and two alarm modules 1308 a,1308 b. Each measurement module 1302 a, 1302 b is similar to thosedescribed above with reference to FIGS. 2-4 and includes a sensor 1314a, 1314 b mounted on a rotational motor.

The modules of the doorway protection system 1300 are communicativelycoupled together to allow information and data from the measurementmodules 1302 a, 1302 b to reach the detection module 1304, and to allowcontrol signals from the detection module 1304 to reach the alarmmodules 1308 a, 1308 b. The communication coupling may be wired orwireless.

Each of the measurement modules 1302 a, 1302 b is associated with arespective one of an outside surface 1310 a and an inside surface 1310 bof a physical structure 1312, e.g., a doorway wall, that includes thedoorway of the hangar. For example, the first measurement module 1302 amay be associated with the outside surface 1310 a of the doorway wall1312 and the second measurement module 1302 b may be associated with theinside surface 1310 b of the doorway wall. The respective associationsbetween the measurement modules 1302 a, 1302 b and the surfaces 1310 a,1301 b places the measurement modules in a spaced apart relationshipwith the surface. To this end, each measurement modules 1302 a, 1302 b,may be located on a pole or rod that projects outward from the surface1310 a, 1310 b.

Each of the alarm modules 1308 a, 1308 b may be associated with arespective one of the outside surface 1310 a and inside surface 1310 bof the doorway wall 1312 in a vicinity of the doorway. For example, thefirst alarm module 1308 a may be associated with the outside surface1310 a of the doorway wall 1312 near a top edge 1320 b of the doorwayand the second alarm module 1308 b may be associated with the insidesurface 1310 b of the doorway wall 1312 also near the top edge of thedoorway. In an alternative configuration, the alarm modules 1308 a, 1308b may be integrated with a respective measurement modules 1302 a, 1302b.

With continued reference to FIGS. 13A-13C, in one configuration thedetection module 1304 defines a monitored frame 1318 a, 1318 b for eachrespective outside surface 1310 a and inside surface 1310 b of thedoorway wall 1312. These monitored frames 1318 a, 1318 b are notphysical in nature, but are instead virtual frames, each of which isgenerally parallel to and spaced apart from its respective surface 1310a, 1310 b. These monitored frames 1318 a, 1318 b are defined bymonitored frame data sets 1306 a, 1306 b that include a number ofbaseline measurements, each corresponding to a distance between a sensor1314 a, 1314 b spaced apart from a respective surface 1310 a, 1310 b anda virtual end of a monitored frame. The distance between each surface1310 a, 1310 b and its respective monitored frame 1318 a, 1318 b definesa protected space for the doorway wall 1312. These distances are definedby the length of the pole to which each sensors 1314 a, 1314 b isattached. The distance is typically in the range of 1 to 3 feet.

Each monitored frame 1318 a, 1318 b is defined by a number of virtualends. For example, the outside monitored frame 1318 a may be definedby: 1) a pair of generally parallel and spaced apart first-side virtualends 1322 a ₁, 1322 a 2, one of which is generally aligned with thefirst edge 1320 a of the doorway wall 1312, 2) a pair of generallyparallel and spaced apart second-side virtual ends 1322 c ₁, 1322 c 2,one of which is generally aligned with the second edge 1320 c of thedoorway wall, 3) a pair of generally parallel and spaced apart topvirtual ends 1322 b 1, 1322 b 2, one of which is generally aligned withthe top edge 1320 b of the doorway wall, and 4) a pair of bottom virtualends 1322 d, 1322 e, one on either side of the doorway wall andgenerally aligned with the bottom of the surface 1310 a. The distancesbetween the spaced apart first-side virtual ends 1322 a ₁, 1322 a 2, thespaced apart second-side virtual ends 1322 c ₁, 1322 c 2, and the spacedapart top virtual ends 1322 b 1, 1322 b 2 define the area size of themonitored frame 1318 a, 1318 b and thus define a protected area for thedoorway wall 1312 around the doorway. These distances are typically inthe range of 1 to 3 feet; and in one configuration, the distance betweenthe top virtual ends 1322 b 1, 1322 b 2 is less than the distancesbetween the first-side virtual ends 1322 a ₁, 1322 a 2 and thesecond-side virtual ends 1322 c ₁, 1322 c 2.

During a detection phase of the doorway protection system 1300,subsequent distance measurements are obtained by the measurement modules1302 a, 1302 b and provided to the detection module 1306. From thesesubsequent measurements, the detection module 1306 determines if anobject has breached or crossed through a monitored frame 1318 a, 1318 b.If a breach or intrusion has occurred, the detection module 1306 outputsan activation signal to a corresponding alarm module 1308 a, 1308 b. Thealarm module 1308 a, 1308 b may be visual or aural in nature. Forexample, the alarm module 1308 a, 1308 b may include lights configuredto flash and/or speakers configured to output an alarm sound.

Having thus described the configuration and operation of the doorwayprotection system 1300 at a general level, a more detailed descriptionfollows.

With reference to FIG. 14, the doorway protection system 1300 includesone or more measurement modules 1302 a, 1302 b, a detection module 1304including one or more monitored frame data sets 1306 a, 1306 b, and oneor more alarm modules 1308 a, 1308 b. The number of measurement modules1302 a, 1302 b and alarm modules 1308 a, 1308 b typically corresponds tothe number of surfaces of the doorway wall 1312 for which protection issought, which is usually two. The detection module 1304 may be embodiedin a controller 1402 having a memory 1404 and a processor 1406programmed to implement the features of the detection module 1304 asdisclosed herein.

As described above, each of the measurement modules 1302 a, 1302 bincludes a sensor 1314 a, 1314 b that is configured to provide distancemeasurements between itself and objects, e.g., aircraft wing, etc., nearthe sensor. Each sensor 1314 a, 1314 b in turn, is associated with amotor 1316 a, 1316 b that is configured to rotate at a particularrotation rate in accordance with a control signal output by thecontroller 1402.

In one configuration, the sensor 1314 a, 1314 b is a light detection andranging (LIDAR) sensor that utilizes a pulsed laser light and time offlight calculations to determine distance measurements. An example LIDARsensor 1314 a, 1314 b that may be employed by the doorway protectionsystem 1300 is a RPLIDAR A3 sensor manufactured by Slamtec. In anotherconfiguration, the sensor 1314 a, 1314 b may be a RPLIDAR A29 sensor,also manufactured by Slamtec. In yet another configuration, the sensor1314 a, 1314 b may be a TG30 LIDAR manufactured by YDLIDAR. In eitherconfiguration, the sensor 1314 a, 1314 b is configured to output data1412 a, 1412 b corresponding to distance measurements at a programmablerate. For example, the sensors 1314 a, 1314 b may be programmed tooutput distance measurements 1412 a, 1412 b at a rate of one perone-thirty-six-hundredths (1/3600) of a second, which equates to 3600measurements per second.

The monitored frame data sets 1306 a, 1306 b include a list of baselinemeasurements that define a corresponding one of the monitored frames1318 a, 1318 b. To this end, a set of baseline measurements is providedfor each degree of rotation at which a measurement module 1302 a, 1302 bis configured to obtain a measurement. Each baseline measurement in aset of baseline measurements includes 1) a distance between ameasurement module and one of the plurality of virtual ends 1322 a ₁,1322 a ₂, 1322 b ₁, 1322 b ₂, 1322 c ₁, 1322 c ₂, 1322 d, 1322 e of themonitored frame, and 2) is identified by an angle parameter.

With reference to FIG. 15, a frame corresponding to the monitored frame1318 a shown in FIG. 13B includes eight virtual ends 1322 a ₁, 1322 a ₂,1322 b ₁, 1322 b ₂, 1322 c ₁, 1322 c ₂, 1322 d, 1322 e. The monitoredframe data set 1306 a for this monitored plane 1318 a includes a set ofbaseline measurements for a number of one-tenth degree rotations of themeasurement module 1302 a. In the configuration shown in FIG. 15, themonitored frame data set 1306 a includes a set of baseline measurementsfor each one-tenth degree of rotation of the measurement module 1302 abetween 90 degrees and 270 degrees corresponding to the lower half ofthe circle of rotation of the measurement module. Measurements between 0degrees and 89.9 degrees and between 270.1 and 360 degrees correspondingto the upper half of the circle of rotation are not relevant as they areoutside of the monitored frame 1318 a defined by the virtual ends 1322 a₁, 1322 a ₂, 1322 b ₁, 1322 b ₂, 1322 c ₁, 1322 c ₂, 1322 d, 1322 e. Aset of baseline measurements may include one or three individualbaseline measurements.

For clarity of illustration, only four sets of baseline measurements1510 a are shown in FIG. 15. These measurements include:

1) a set of baseline measurements 1510 a ₉₀₀ corresponding to a 90degree rotation point of the measurement module 1302 a, which includes asingle baseline measurement set to a value equal to the distance betweenthe measurement module and the virtual end 1322 c ₁ of the monitoredframe 1318 a, which is identified as point “a”;

2) a set of baseline measurements 1510 a ₁₂₀₀ corresponding to a 120degree rotation point of the measurement module 1302 a, which includesthree baseline measurements including one set to a value equal to thedistance between the measurement module and the virtual end 1322 b ₂ ofthe monitored frame 1318 a, which is identified as point “a”, a secondone set to a value equal to the distance between the measurement moduleand the virtual end 1322 c ₂ of the monitored frame 1318 a, which isidentified as point “b”, and a third one set a value equal to thedistance between the measurement module and the virtual end 1322 c ₁ ofthe monitored frame 1318 a, which is identified as point “c”;

3) a set of baseline measurements 1510 c ₁₈₀₀ corresponding to a 180degree rotation point of the measurement module 1302 a includes a singlebaseline measurement set to a value equal to the distance between themeasurement module and the virtual end 1322 b ₂ of the monitored plane1318 a, which is identified as point “a”; and

4) a set of baseline measurements 1510 a ₂₇₀₀ corresponding to a 270degree rotation point of the measurement module 1302 a, which includes asingle baseline measurement set to a value equal to the distance betweenthe measurement module and the virtual end 1322 a ₁ of the monitoredframe 1318 a, which is identified as point “a”.

In the example of FIG. 15, the monitored frame data set 1306 a comprises1800 sets of instances or data points, each defined by a distancemeasurement and an angle parameter. The monitored frame data sets 1306 bmay be similarly defined. Portions of an example monitored frame dataset 1306 a are provided in Table 3.

TABLE 3 Distance “a” Distance “b” Distance “c” Angle parametermeasurement measurement measurement (degree of rotation) (millimeters)(millimeters) (millimeters) 90.0 14000 — — 90.1 14000 — — 90.2 14010 — —90.3 14010 — — 90.4 14015 — — . . . . . . . . . . . . 120.0 600 1350016000 120.1 600 13500 16000 120.2 605 13550 16050 120.3 605 13550 16050120.4 608 13558 16058 . . . . . . . . . . . . 180.0 400 — — 180.1 400 —— 180.2 405 — — 180.3 405 — — 180.4 410 — —

The detection module 1304 receives subsequent measurements 1412 a, 1412b from each of measurement modules 1302 a, 1302 b and evaluates thesubsequent measurements relative to the sets of baseline measurements.To this end, the detection module 1304 is configured to control rotationof the motor 1316 a, 1316 b of each respective measurement module 1302a, 1302 b so its associated sensor rotates at a set rate correspondingto the same rate used to define the sets of baseline measurements. Forexample, the detection module 1304 may be programmed to output a controlsignal to each motor 1316 a, 1316 b that causes the motor and itassociated sensor 1314 a, 1314 b to rotate 360 degrees per second. Thus,rotating at a rate of 360 degrees per second and providing distancemeasurements 1412 a, 1412 b at a rate of 3600 per second, themeasurement modules 1302 a, 1302 b provide 3600 distance measurementsfor each 360 degree rotation of the sensor. In other words, themeasurement modules 1302 a, 1302 b provide a distance measurement 1412a, 1412 b every one-tenth of a degree of rotation.

For each doorway wall surface 1310 a, 1310 b having an associatedmonitored frame 1318 a, 1318 b the detection module 1304 may evaluatesubsequent distance measurements 1412 a, 1412 b provided by themeasurement module 1302 a, 1302 b associated with that surface relativeto its corresponding sets of baseline measurements included in therelative monitored frame data set 1306 a, 1306 b to determine if anobject has penetrated or intruded the monitored frame. An object may beconsidered to breach or intrude a monitored frame 1318 a, 1318 b when apart or portion of the object passes through the frame. The detectionmodule 1304 detects such intrusions by comparing, in real time, one ormore subsequent measurements 1412 a, 1412 b to a corresponding set ofbaseline measurements to determine an intrusion state for each monitoredplane.

In one configuration, and with reference to FIG. 15 and Table 3, thedetection module 1304 may conclude that an intrusion of a monitoredframe 1318 a, 1318 b occurred when a subsequent measurement at aparticular angle of rotation is less than measurement “a” for that angleof rotation. The detection module 1304 may also conclude that anintrusion of a monitored frame 1318 a, 1318 b occurred when a subsequentmeasurement at a particular angle of rotation is greater thanmeasurement “b” for that angle of rotation but less than measurement “c”for that angle of rotation. In this configuration, the detection module1304 ignores any subsequent measurements for an angle of rotation thatare between measurements “a” and “b” for that angle. Accordingly thedetection module 1304 does not activate an alarm when an object passesthrough the doorway.

FIG. 16 is a flowchart of a method of protecting against impact betweena vehicle and a physical structure, e.g., doorway wall, of a facilitythat has opening or doorway for the vehicle to pass through. The methodmay be performed by the doorway protection system 900 of FIGS. 13A-13Cand 14.

At block 1602, a monitored frame 1318 a, 1318 b is defined for at leastone of the inside surface 1310 a and the outside surface 1310 b of thephysical structure 1312, e.g., doorway wall, that includes the openingor doorway 1303. The monitored frame is defined by sets of baselinemeasurements. For example, with reference to FIG. 15, an exteriormonitored frame 1318 a is defined by sets of baseline measurements 1510a, each of which is identified by an angle parameter and includes atleast one baseline measurement that corresponds to a distance between asensor 1314 a spaced apart from the exterior surface of the doorway walland one of a plurality of virtual ends 1322 a ₁, 1322 a ₂, 1322 b ₁,1322 b ₂, 1322 c ₁, 1322 c ₂, 1322 d, 1322 e of the monitored frame. Inone configuration, and continuing with the monitored plane 1318 a shownin FIG. 15, the angle parameter identifying a particular set of baselinemeasurement 1510 a is a n degree of rotation of the sensor 1314 a.

With reference to FIG. 13B, the doorway 1303 is defined by a pluralityof edges of the doorway wall 1312. These edges include a first verticalside edge 1320 a, a second vertical side edge 1320 c opposite the firstside edge, and a top horizontal edge 1230 b spanning the first side edgeand the second side edge. The virtual ends 1322 a ₁, 1322 a ₂, 1322 b ₁,1322 b ₂, 1322 c ₁, 1322 c ₂, 1322 d, 1322 e of the monitored frame 1318a include a first inner end 1322 a ₁ that is generally aligned with ornear the first vertical side edge 1320 a of the doorway 1303, a secondinner end 1322 c ₁ that is generally aligned with or near the secondside edge 1320 c of the opening, and an upper end 1322 b ₁ that isgenerally aligned with or near the top edge 1320 b of the opening.

Returning to FIG. 16, at block 1604, a subsequent measurement isobtained. To this end, a sensor 1314 a, 1314 b is rotated relative tothe surface 1310 a, 1310 b and a plurality of subsequent measurementsare obtained. For example, a subsequent measurement may be obtained atevery n degree of rotation of the sensor.

At block 1606, the subsequent measurement is evaluated relative to acorresponding set of baseline measurement to determine if a criterionindicative of an intrusion of the monitored plane is satisfied. In oneconfiguration, the criterion may be satisfied when a subsequentmeasurement at an n degree of rotation is less than a value that isbased on the corresponding baseline measurement identified by the ndegree of rotation. For example, with reference to FIGS. 13B and 15, ifan object 1305, e.g., tip of an aircraft, enters into a top portion of amonitored frame 1318 a, a subsequent measurement 1510 a _(x) obtained bythe sensor 1314 a at an n degree of rotation that aligns the sensor beamwith the object will result in a subsequent measurement less than thebaseline measurement “a” corresponding to that n degree of rotation.

In another configuration, if an object 1307, e.g., end of an aircraftwing, enters into a side portion of a monitored frame 1318 a, asubsequent measurement 1510 a _(y) obtained by the sensor 1314 a at an ndegree of rotation that aligns the sensor beam with the object willresult in a subsequent measurement between the baseline measurement “b”included in the corresponding set of baseline measurements identified bythe n degree of rotation and the baseline measurement “c” included inthe corresponding set of baseline measurements identified by the ndegree of rotation.

At block 1608, an alarm associated with an alarm module 908 a, 908 b isactivated when the criterion is satisfied. After an alarm is activated,another measurement of the subsequent measurement 1510 a _(x), 1510 a_(y) that triggered the alarm is obtained and evaluated relative to thecorresponding set of baseline measurements to determine if the criterionindicative of the intrusion of the monitored plane 1318 a, 1318 b is nolonger satisfied. At block 1610, the alarm is deactivated when thecriterion is no longer satisfied. These other measurement of thesubsequent measurement 1510 a _(x), 1510 a _(y) may be obtained duringeach rotation of the sensor 914 a.

While some protection systems, such as those disclosed with reference toFIGS. 2-8, focus on protection of the solid or closed walls of afacility, and other protection systems, such as those described withreference to FIGS. 9A-16, focus on protection of doorway walls of suchfacilities, features and components of the respective protection systemsmay be combined to form a single protection system that protects theentirety of a facility.

The protection systems have been described and depicted herein in termsof different types of modules, e.g., measurement modules, detectionmodule, and alarm modules, for purposes of aiding in various functionaldescriptions of the system. Regarding the physical structure of theprotection systems, these different modules are not necessarilyphysically separate from each other may be all contained in one physicalunit that communicates with a computer.

The various aspects of this disclosure are provided to enable one ofordinary skill in the art to practice the present invention. Variousmodifications to exemplary embodiments presented throughout thisdisclosure will be readily apparent to those skilled in the art. Thus,the claims are not intended to be limited to the various aspects of thisdisclosure, but are to be accorded the full scope consistent with thelanguage of the claims. All structural and functional equivalents to thevarious components of the exemplary embodiments described throughoutthis disclosure that are known or later come to be known to those ofordinary skill in the art are expressly incorporated herein by referenceand are intended to be encompassed by the claims. No claim element is tobe construed under the provisions of 35 U.S.C. § 112, sixth paragraph,unless the element is expressly recited using the phrase “means for” or,in the case of a method claim, the element is recited using the phrase“step for.”

What is claimed is:
 1. A method of protecting against impact between avehicle and a physical structure of a facility, the physical structurehaving an opening for the vehicle to pass through, the opening definedby a plurality of edges of the physical structure, the methodcomprising: for at least one of the plurality of edges, defining amonitored plane relative to the edge, the monitored plane defined by aplurality of baseline measurements, wherein each of the plurality ofbaseline measurements: 1) corresponds to a distance between a sensorspaced apart from the edge and one of a plurality of virtual ends of themonitored plane, and 2) is identified by an angle parameter; obtaining asubsequent measurement; evaluating the subsequent measurement relativeto a corresponding baseline measurement to determine if a criterionindicative of an intrusion of the monitored plane is satisfied; andactivating an alarm when the criterion is satisfied.
 2. The method ofclaim 1, wherein the angle parameter identifying a particular baselinemeasurement is a n degree of rotation of the sensor.
 3. The method ofclaim 2, wherein obtaining a subsequent measurement comprises: rotatingthe sensor relative to the edge, and obtaining a plurality of subsequentmeasurements, one at every n degree of rotation of the sensor.
 4. Themethod of claim 3, wherein the criterion is satisfied when thesubsequent measurement at an n degree of rotation is less than a valuethat is based on the corresponding baseline measurement identified bythe n degree of rotation.
 5. The method of claim 1, wherein theplurality of virtual ends of the monitored plane comprises an inside endspaced a distance from an inside surface of the physical structure, andan outside end spaced a distance from an outside surface of the physicalstructure.
 6. The method of claim 1, wherein: the plurality of edges ofthe physical structure comprise a first side edge, a second side edgeopposite the first side edge, and a top edge spanning the first sideedge and the second side edge; and the plurality of virtual ends of themonitored plane for either of the first side edge or the second sideedge further comprises a top end spaced a distance from the top edge ofthe opening.
 7. The method of claim 1, wherein: the plurality of edgesof the physical structure comprise a first side edge, a second side edgeopposite the first side edge, and a top edge spanning the first sideedge and the second side edge; and the plurality of virtual ends for themonitored plane for the top edge further comprises a first end adistance from the first side edge and a second end a distance from thesecond side edge.
 8. The method of claim 1, further comprising: afteractivating the alarm, evaluating another measurement of the subsequentmeasurement relative to the corresponding baseline measurement todetermine if the criterion indicative of the intrusion of the monitoredplane is no longer satisfied; and deactivating the alarm when thecriterion is no longer satisfied.
 9. A system for protecting againstimpact between a vehicle and a physical structure of a facility, thephysical structure having an opening for the vehicle to pass through,the opening defined by a plurality of edges of the physical structure,the system comprising: a measurement module configured to be spacedapart from one of the plurality of edges and further configured to:rotate relative to the edge; and obtain a plurality of measurements,wherein each of the plurality of measurements corresponds to a distancefrom the measurement module; a detection module coupled to themeasurement module and comprising a definition module that defines amonitored plane relative to the edge, the monitored plane defined by aplurality of baseline measurements, wherein each of the plurality ofbaseline measurements: 1) corresponds to a distance between themeasurement module and one of a plurality of virtual ends of themonitored plane, and 2) is identified by an angle parameter, thedetection module configured to: obtain a subsequent measurement from themeasurement module; associate an angle parameter with the subsequentmeasurement; evaluate the subsequent measurement relative to acorresponding baseline measurement having a same angle parameter todetermine if a criterion indicative of an intrusion of the monitoredplane is satisfied; and output an alarm activation signal when thecriterion is satisfied.
 10. The system of claim 9, wherein themeasurement module comprises: a motor configured to rotate at a rotationrate; and a sensor coupled to the motor and configured to output a beamevery n degrees of rotation.
 11. A method of protecting against impactbetween a vehicle and a physical structure of a facility, the physicalstructure having an inside surface, and outside surface, and an openingfor the vehicle to pass through, the method comprising: for at least oneof the inside surface and the outside surface, defining a monitoredframe relative to the surface, the monitored frame defined by aplurality of sets of baseline measurements, wherein each of theplurality of sets of baseline measurements is identified by an angleparameter and includes at least one baseline measurement thatcorresponds to a distance between a sensor spaced apart from the surfaceand one of a plurality of virtual ends of the monitored frame; obtaininga subsequent measurement; evaluating the subsequent measurement relativeto a corresponding set of baseline measurements to determine if acriterion indicative of an intrusion of the monitored frame issatisfied; and activating an alarm when the criterion is satisfied. 12.The method of claim 11, wherein the angle parameter identifying aparticular baseline measurement is a n degree of rotation of the sensor.13. The method of claim 12, wherein obtaining a subsequent measurementcomprises: rotating the sensor relative to the surface, and obtaining aplurality of subsequent measurements, one at every n degree of rotationof the sensor.
 14. The method of claim 12, wherein the criterion issatisfied when the subsequent measurement at an n degree of rotation isless than a value that is based on a baseline measurement included inthe corresponding set of baseline measurements identified by the ndegree of rotation.
 15. The method of claim 12, wherein the criterion issatisfied when the subsequent measurement at an n degree of rotation isbetween a first value that is based on a first baseline measurementincluded in the corresponding set of baseline measurements identified bythe n degree of rotation and a second value that is based on a secondbaseline measurement included in the corresponding set of baselinemeasurements identified by the n degree of rotation.
 16. The method ofclaim 11, wherein: the opening is defined by a plurality of edgescomprising a first side edge, a second side edge opposite the first sideedge, and a top edge spanning the first side edge and the second sideedge; and the plurality of virtual ends of the monitored frame comprisesa first inner end generally aligned with or near the first side edge ofthe opening, a second inner end generally aligned with or near thesecond side edge of the opening, and an upper end generally aligned withor near the top edge of the opening.
 17. The method of claim 11, furthercomprising: after activating the alarm, evaluating another measurementof the subsequent measurement relative to the corresponding set ofbaseline measurements to determine if the criterion indicative of theintrusion of the monitored frame is no longer satisfied; anddeactivating the alarm when the criterion is no longer satisfied.
 18. Asystem for protecting against impact between a vehicle and a physicalstructure of a facility, the physical structure having an insidesurface, an outside surface, and an opening for the vehicle to passthrough, the system comprising: a measurement module configured to bespaced apart from at least one of the inside surface and the outsidesurface and further configured to: rotate relative to the surface; andobtain a plurality of measurements, wherein each of the plurality ofmeasurements corresponds to a distance from the measurement module; adetection module coupled to the measurement module and comprising adefinition module that defines a monitored frame relative to thesurface, the monitored frame defined by a plurality of sets of baselinemeasurements, wherein each of the plurality of sets of baselinemeasurements is identified by an angle parameter and includes at leastone baseline measurement that corresponds to a distance between a sensorspaced apart from the surface and one of a plurality of virtual ends ofthe monitored frame, the detection module configured to: obtain asubsequent measurement from the measurement module; associate an angleparameter with the subsequent measurement; evaluate the subsequentmeasurement relative to the set of baseline measurements identified bythe angle parameter associated with the subsequent measurement todetermine if a criterion indicative of an intrusion of the monitoredframe is satisfied; and output an alarm activation signal when thecriterion is satisfied.
 19. The system of claim 18, wherein themeasurement module comprises: a motor configured to rotate at a rotationrate; and a sensor coupled to the motor and configured to output a beamevery n degrees of rotation.